The purpose of this project is to apply the latest bacterial technology to the cloning and analysis genomic DNA sequences involved in the regulation of globin gene expression in human, sheep and mice. In collaboration with the Clinical Hematology Branch, near full-length complementary DNA copies (cDNA) of sheep beta B, beta C and gamma globin messenger RNA (mRNA) sequences have been cloned into the plasmid pMB9, and subjected to extensive endonuclease restriction and hybridization analysis. Recently developed methods for cloning of genomic DNA sequences via the lambda packaging system have been established to the point where we are about to commence cloning of human thalassemic and sheep globin sequences from genomic DNA. As a possible model system for the control of eukaryotic gene expression, studies on the parameters affecting translocation of the ampicillin transposon (Tn3) in E. coli have been pursued. The inhibitory effect of temperature on Tn3 translocation has been characterized and used to demonstrate the dependence of translocation on concurrent protein synthesis.